Pop-off mechanisms as renoprotective mediators in children with posterior urethral valves: A systematic review and meta-analysis.

ABSTRACT

BACKGROUND: Pop-off mechanisms are potential pressure-relieving mediators in patients diagnosed with posterior urethral valves (PUV). This systematic review aimed to synthesize the existing evidence regarding the protective effect of pop-off mechanisms on renal function in children with PUV. METHODS: We conducted a systematic review of the literature that involved an extensive search in the main databases of the medical bibliography. Three independent reviewers selected the relevant articles. Methodological quality was rated using the Newcastle Ottawa Scale index. We used random meta-analyses to compare different outcomes (serum creatine, Nadir serum creatinine, and Chronic Kidney Disease) between children with PUV and pop-off mechanisms and those with PUV without pop-off mechanisms. RESULTS: 10 studies with data from 896 participants were included in this review. Seven articles reported serum creatinine values for each group and 3 of them found significant differences between groups. The random-effects meta-analysis for serum creatinine showed significant lower mean (diff = -52.88 µmol/L [95 % CI -73.65 to -32.11]) in the group of children with pop-off mechanisms, and the random-effects meta-analysis for Nadir serum creatinine showed a marginally significantly lower mean in the group of children with pop-off mechanisms (diff = -12.00 µmol/L [95 % CI -24.04 to 0.04]). The random-effect meta-analysis for Chronic Kidney Disease resulted in a significant risk reduction for the group of children with pop-off mechanisms (odds ratio = 0.48 [95 % CI 0.23 to 0.98]). CONCLUSIONS: Children with PUV and pop-off mechanisms show better renal function and lower risk of Chronic Kidney Disease than those with PUV without pop-off mechanisms suggesting these mechanisms may act as renoprotective mediators. The high heterogeneity between studies in the assessment of renal function and long-term outcomes calls for a cautious interpretation of these findings. Future studies that stratify by different types of pop-off mechanisms and use standardized metrics, such as Nadir creatinine, are needed.